Re: [PATCH] pinctrl: intel: Initialize GPIO properly when used through irqchip

[Chris Chiu <chiu@xxxxxxxxxxxx>]

On Mon, Nov 20, 2017 at 11:19 PM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> When a GPIO is requested using gpiod_get_* APIs the intel pinctrl driver
> switches the pin to GPIO mode and makes sure interrupts are routed to
> the GPIO hardware instead of IOAPIC. However, if the GPIO is used
> directly through irqchip, as is the case with many I2C-HID devices where
> I2C core automatically configures interrupt for the device, the pin is
> not initialized as GPIO. Instead we rely that the BIOS configures the
> pin accordingly which seems not to be the case at least in Asus X540NA
> SKU3 with Focaltech touchpad.
>
> When the pin is not properly configured it might result weird behaviour
> like interrupts suddenly stop firing completely and the touchpad stops
> responding to user input.
>
> Fix this by properly initializing the pin to GPIO mode also when it is
> used directly through irqchip.
>
> Reported-by: Daniel Drake <drake@xxxxxxxxxxxx>
> Reported-by: Chris Chiu <chiu@xxxxxxxxxxxx>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> ---
> Chris, Daniel,
>
> Could you check that this still solves the issue and maybe provide your
> Tested-by? Thanks!
>

I've verified on X540NA here and it's working fine w/o any abnormal touchpad
stop.

Tested-by: Chris Chiu <chiu@xxxxxxxxxxxx>
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